ADVANCES IN METAL-CUTTING TOOL MATERIALS

The dominant tool material for metal cutting with tooling using indexa ble inserts is the coated cemented carbide. There is currently a stron g development in coating technology for carbide inserts and most moder n metal cutting grades are manufactured with multi-layer coatings to g ive optimum wear reduction in the intended application area of each gr ade. The development of new coating processes has led to new requireme nts on the underlying carbide in order to utilize the full potential o f the coating. As a result, there is also a strong development in ceme nted carbide technology for metal cutting applications, frequently inc luding the formation of surface gradient structures. In modern metal c utting grades, the coating and substrate have been tailored to each ot her and carefully optimized for the intended application area together with insert macro-and micro-geometry. Using this type of application- oriented approach, it is possible to further improve the performance o f modern tool materials in machining. In spite of the significantly im proved performance of the modern coated carbide grades, there is still a strong growth in other high-performance tool materials such as cerm ets, ceramics, cubic boron nitride and diamond. Coating development ha s also become important for these materials and new cermet and ceramic grades with coatings have been successfully introduced during the las t 5 years. In addition, 2 completely new tool material concepts, diamo nd coating by a plasma CVD process and multi-corner inserts technology for cBN inserts, have recently been introduced on the market. However , further developments in tool materials will be required to meet the future needs of the manufacturing industry, including demanding applic ations such as hard part machining, high productivity machining, dry m achining, superfinishing and new difficult-to-machine work materials.